#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    init();
    connect(ui->treeWidget,SIGNAL(itemChanged(QTreeWidgetItem*,int)),
            this,SLOT(treeItemChanged(QTreeWidgetItem *,int)));
}

Widget::~Widget()
{
    delete ui;
}

void Widget::init()
{
    ui->treeWidget->clear();
    //first group
    QTreeWidgetItem *group1 = new QTreeWidgetItem(ui->treeWidget);
    group1->setText(0,"group1");
    group1->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    group1->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem11 = new QTreeWidgetItem(group1);
    subItem11->setText(0,"subItem11");
    subItem11->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem11->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem12 = new QTreeWidgetItem(group1);
    subItem12->setText(0,"subItem12");
    subItem12->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem12->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem13 = new QTreeWidgetItem(group1);
    subItem13->setText(0,"subItem13");
    subItem13->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem13->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem14 = new QTreeWidgetItem(group1);
    subItem14->setText(0,"subItem14");
    subItem14->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem14->setCheckState(0,Qt::Unchecked);
    //second group
    QTreeWidgetItem *group2 = new QTreeWidgetItem(ui->treeWidget);
    group2->setText(0,"group2");
    group2->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    group2->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem21 = new QTreeWidgetItem(group2);
    subItem21->setText(0,"subItem21");
    subItem21->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem21->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem22 = new QTreeWidgetItem(group2);
    subItem22->setText(0,"subItem22");
    subItem22->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem22->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem23 = new QTreeWidgetItem(group2);
    subItem23->setText(0,"subItem23");
    subItem23->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem23->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem24 = new QTreeWidgetItem(group2);
    subItem24->setText(0,"subItem24");
    subItem24->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem24->setCheckState(0,Qt::Unchecked);
}

void Widget::treeItemChanged(QTreeWidgetItem *item,int column)
{
    QString itemTest = item->text(0);
    //if choose
    if(Qt::Checked == item->checkState(0))
    {
        QTreeWidgetItem *parent = item->parent();
        int count = item->childCount();
        if(count>0)
        {
            for(int i = 0;i<count;i++)
            {
                //if child point also choosed
                item->child(i)->setCheckState(0,Qt::Checked);
            }
        }
        else
        {
            updateParentItem(item);
        }
    }
    else if(Qt::Unchecked == item->checkState(0))
    {
        int count = item->childCount();
        if(count>0)
        {
            for(int i = 0;i<count;i++)
            {
                item->child(i)->setCheckState(0,Qt::Unchecked);
            }
        }
        else
        {
            updateParentItem(item);
        }
    }
}
void Widget::updateParentItem(QTreeWidgetItem *item)
{
    QTreeWidgetItem *parent = item->parent();
    if(parent == NULL)
    {
        return;
    }
    //number of choosed child point
    int selectCount = 0;
    int childCount = parent->childCount();
    for(int i = 0;i<childCount;i++)
    {
        QTreeWidgetItem *childItem = parent->child(i);
        if(childItem->checkState(0) == Qt::Checked)
        {
            selectCount++;
        }
    }
    if(selectCount <= 0)
    {
        //unselected state
        parent->setCheckState(0,Qt::Unchecked);
    }
    else if(selectCount > 0 && selectCount < childCount)
    {
        //partial selected state
        parent->setCheckState(0,Qt::PartiallyChecked);
    }
    else if(selectCount == childCount)
    {
        //checked state
        parent->setCheckState(0,Qt::Checked);
    }

}
